try these solutions:<br /><br />Solution 1: End Acrobat.exe or AcroRd32.exe in the Task Manager<br /><br />1. Press Ctrl+Alt+Delete.<br />2. Click Task Manager choose the Processes tab and select either Acrobat.exe or AcroRd32.exe in the list of tasks running .<br />4. Click End Process and choose Yes to Task Manager warning.<br />5. Click on a PDF in a browser window.<br /><br />Solution 2: Remove older versions of Acrobat and then install Acrobat.<br />If you have older versions of Acrobat or Adobe Reader installed, remove them using the Add/Remove Programs utility, and then install only one of the programs.<br />1. Close all applications currently running on your system, including other Adobe applications, MS Office applications, and browser windows. <br />2. Run the uninstaller: <br />1. Go to Start Menu > Control Panel. <br />2. Double-click Programs And Features (Windows Vista) or Add Or Remove Programs (Windows XP). <br />3. Select the Acrobat or Adobe Reader, click Remove, and follow the on-screen instructions. <br />3. Remove all files related to Acrobat or Reader from your system: <br />1. Go to Start Menu > My Computer. <br />2. In the Address bar near the top of the window type one of the following: <br /> On Windows Vista, type: \Users\<user_name>\AppData\Roaming\Adobe <br /> On Windows XP, type: \Documents and Settings\<user_name>\Application Data\Adobe <br />3. Delete files and folders with Acrobat or Adobe Reader in the name. <br />4. In the Address bar near the top of the window type one of the following: <br /> On Windows Vista, type: \Users\<user_name>\AppData\Local\Adobe <br /> On Windows XP, type: \Documents and Settings\<user_name>\Local Settings\Application Data\Adobe <br />5. Delete files and folders with Acrobat or Reader in the name. <br />6. Reinstall either Acrobat 8 and not Reader 9 or reinstall Acrobat 9 and not Reader 8.x.